In this talk we will report on some recent joint work with Josh Kline, Riikka Korte, Marie Snipes and Nages Shanmugalingam, concerning the Neumann problem in PI spaces, and a new definition of fractional p-Laplacians in arbitrary doubling measure metric space. We extend some earlier work by Lukas Maly and Nages Shanmugalingam, proving well posedness in appropriate Lebesgue classes for the Neumann problem for p-Laplacians, and then leverage these results to prove existence, stability and regularity for the corresponding non homogeneous non-local PDE.